Article
Nanoscience & Nanotechnology
Min Seong Kim, Hyung Tae Kim, Hyukjoon Yoo, Dong Hyun Choi, Jeong Woo Park, Tae Sang Kim, Jun Hyung Lim, Hyun Jae Kim
Summary: This study suggests that introducing an oxygen scavenger layer (OSL) in a-IGZO TFT can significantly improve its electrical characteristics and stability, especially at low temperatures. The enhancement is mainly attributed to the presence of hafnium (Hf) in the OSL, which absorbs oxygen ions to address interface issues between the front channel and OSL.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Seong-Hyun Hwang, Kie Yatsu, Dong-Ho Lee, Ick-Joon Park, Hyuck-In Kwon
Summary: The study found that reducing the thickness of the aluminum oxide passivation layer can significantly improve the radiation hardness of IGTO thin-film transistors. Thin-film transistors passivated by Al2O3 prepared by sputtering exhibited higher radiation resistance.
APPLIED SURFACE SCIENCE
(2022)
Article
Materials Science, Ceramics
Seo-Hyun Moon, Soo-Hyun Bae, Young -Ha Kwon, Nak-Jin Seong, Kyu-Jeong Choi, Sung-Min Yoon
Summary: Bi-layered channel structures were introduced to enhance the carrier mobility of oxide thin film transistors. The use of IZO/IGZO bi-layered channel resulted in the highest carrier mobility when the film thickness and ALD sub-cyclic ratio were optimized. The optimum cationic compositions of the IZO and IGZO layers were also determined.
CERAMICS INTERNATIONAL
(2022)
Review
Engineering, Manufacturing
Hye-Mi Kim, Dong-Gyu Kim, Yoon-Seo Kim, Minseok Kim, Jin-Seong Park
Summary: This article provides an overview of the history and importance of ALD-based oxide semiconductors, discusses the advantages of ALD in oxide semiconductor deposition, and explains the challenges of scaling oxide semiconductors and ALD for industrial applications.
INTERNATIONAL JOURNAL OF EXTREME MANUFACTURING
(2023)
Article
Chemistry, Multidisciplinary
Mengwei Si, Yaoqiao Hu, Zehao Lin, Xing Sun, Adam Charnas, Dongqi Zheng, Xiao Lyu, Haiyan Wang, Kyeongjae Cho, Peide D. Ye
Summary: This work demonstrates enhancement-mode field-effect transistors using an atomically-deposited amorphous In2O3 channel with thickness as low as 0.7 nm. The controllable thickness of In2O3 at an atomic scale allows for the design of sufficient 2D carrier density in the channel, affecting threshold voltage and channel carrier density. The model of trap neutral level (TNL) explains how the Fermi level aligns in the conduction band of In2O3 due to the quantum confinement effect, as confirmed by density function theory (DFT) calculations.
Article
Chemistry, Physical
Jina Kim, Myeong Gil Chae, Young Joon Han, Jun Choi, Kwan Hyun Cho, Heenang Choi, Bo Keun Park, Taek-Mo Chung, Woongkyu Lee, Jeong Hwan Han
Summary: High-quality polycrystalline SnO films with excellent hole transport characteristics were successfully grown at a low temperature using atomic layer deposition and annealed with intense pulsed light. The crystallinity of the SnO film increased with increasing light pulse number during the annealing process. The surface morphology of the annealed SnO films was smooth and suitable for thin-film transistor fabrication.
APPLIED SURFACE SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Mari Napari, Tahmida N. Huq, David J. Meeth, Mikko J. Heikkil, Kham M. Niang, Han Wang, Tomi Iivonen, Haiyan Wang, Markku Leskela, Mikko Ritala, Andrew J. Flewitt, Robert L. Z. Hoye, Judith L. MacManus-Driscoll
Summary: High-performance p-type oxide thin film transistors (TFTs) have great potential for semiconductor applications, but often suffer from low hole mobility and high off-state currents. By applying a thin ALD Al2O3 passivation layer on the Cu2O channel and vacuum annealing, the TFT switching characteristics can be improved. Characterization by TEM-EDX and XPS shows that Al2O3 deposition on Cu2O reduces surface and forms a CuAlO2 interfacial layer. This, along with field-effect passivation, leads to improved TFT performance by reducing trap states and electron accumulation in the off-state.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
Dongil Ho, Sunwoo Choi, Hyunwoo Kang, Byungkyu Park, Minh Nhut Le, Sung Kyu Park, Myung-Gil Kim, Choongik Kim, Antonio Facchetti
Summary: Solution-processed metal-oxide thin-film transistors (TFTs) with different metal compositions were investigated for radiation hardness against ionizing radiation exposure. The amorphous zinc-indium-tin oxide (Zn-In-Sn-O or ZITO) was found to be an optimal radiation-resistant channel layer of TFTs due to its structural plasticity, defect tolerance, and high electron mobility. In situ irradiation experiments revealed three degradation mechanisms, including increase in channel conductivity, charge buildup in the interface and dielectric, and trap-assisted tunneling in the dielectric. By employing a radiation-resistant ZITO channel, a thin SiO2 dielectric, and a passivation layer, oxide-based TFTs demonstrated excellent stability under real-time gamma-ray irradiation.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Eun Goo Lee, Yong Jun Gong, Sung-Eun Lee, Hyun-Jae Na, Changik Im, Heebae Kim, Youn Sang Kim
Summary: By incorporating polyaniline (PANI) into metal oxide matrix, the electrical characteristics and stability of metal oxide thin-film transistors (TFTs) can be significantly improved.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Yongbo Wu, Linfeng Lan, Penghui He, Yilong Lin, Caihao Deng, Siting Chen, Junbiao Peng
Summary: The study systematically investigated solution-processed AlOx dielectrics, revealing that the capacitance of AlOx is critically dependent on frequency when annealed at low temperatures and subjected to water treatment. These findings highlight the impact of mobile ions on the frequency-dependent capacitance of solution-processed AlOx dielectrics.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Electrical & Electronic
Leini Wang, Gang He, Wenhao Wang, Xiaofen Xu, Bo He, Xiaoyu Wu, Yongchun Zhang
Summary: This article investigates the performance of solution-derived amorphous cerium oxide (CeO2) as a gate dielectric with a smooth surface. Electrical analysis demonstrates that a 3 nm Al2O3 passivation layer derived from ALD helps reduce leakage current in CeO2 MOS capacitors. Additionally, the article integrates solution-processed In2O3 thin-film transistors (TFTs) based on an optimized Al2O3/CeO2 bilayer dielectric for the first time. Results show that the annealed In2O3/Al2O3/CeO2 TFT demonstrates high performance and stability.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Nanoscience & Nanotechnology
Jae Seok Hur, Min Jae Kim, Seong Hun Yoon, Hagyoung Choi, Chi Kwon Park, Seung Hee Lee, Min Hee Cho, Bong Jin Kuh, Jae Kyeong Jeong
Summary: This paper explores the feasibility of using an indium-gallium oxide film as an alternative channel material for back-end-of-line compatible transistor applications. Thermal annealing was found to convert the microstructure of random polycrystalline indium oxide to an amorphous phase of the indium-gallium oxide film. The study also reveals that the indium-gallium oxide film exhibits improved orientation and grain size at specific doping ratios.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Christophe Avis, Jin Jang
Summary: The impact of NF3 plasma treatment on the HfO2 gate insulator of a-SnOx TFTs was studied. The 10 s-treated TFT demonstrated the best stability, with significantly decreased density of states (DOS) and good HfO2/a-SnOx interface quality.
Article
Engineering, Electrical & Electronic
Seung-Hyun Lim, Tae In Kim, Ick-Joon Park, Hyuck-In Kwon
Summary: This study proposes a synthetic approach to high-performance p-type tellurium (Te) thin-film transistors (TFTs) by using an organic-inorganic hybrid passivation layer. The Te channel is synthesized at room temperature and the passivation layer is formed through the infiltration of inorganic Al2O3 into an SU-8 polymeric template. The hybrid passivation layer significantly improves the device performance compared to a single Al2O3 layer, and the proposed structure shows enhanced long-term stability. This work demonstrates the great potential of high-performance p-type Te TFTs for future electronic applications.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Vishwas Acharya, Nila Pal, Utkarsh Pandey, Akhilesh Kumar Yadav, Mukesh Suthar, Pradip Kumar Roy, Sajal Biring, Bhola N. Pal
Summary: This study demonstrates the deposition of SrTiO3 thin film using a simple solution processed technique and its application in the fabrication of sol-gel derived SnO2 TFT. The high dielectric constant of the SrTiO3 thin film allows the TFT to operate in both low voltage and high voltage ranges. Experimental results show hysteresis-free characteristics in the low voltage range (<2 V), but some hysteresis effects appear in the higher voltage range (>5 V).
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Jeong Woo Park, Won-Gi Kim, Hyukjoon Yoo, Hyung Tae Kim, Dong Hyun Choi, Min Seong Kim, Hyun Jae Kim
Summary: A pulsed green laser was used to activate IGZO TFTs, achieving rapid and selective activation without conventional annealing. The activated IGZO TFTs demonstrated superior electrical characteristics compared to those annealed at 300 degrees C, showing potential for expanding applications in flexible and transparent devices.
JOURNAL OF INFORMATION DISPLAY
(2022)
Article
Engineering, Electrical & Electronic
Akshay Sahota, Harrison Sejoon Kim, Jaidah Mohan, Yong Chan Jung, Heber Hernandez-Arriaga, Dan N. Le, Si Joon Kim, Jang-Sik Lee, Jinho Ahn, Jiyoung Kim
Summary: In this study, a threshold switching (TS) selector with an Ag doping-based nano-polycrystalline ZnO switching layer was developed. The TS selector showed remarkable electroforming-free selection behavior, high device yield, and stable threshold voltage.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Chemistry, Physical
Byung Ha Kang, Kyungho Park, Mike Hambsch, Seongin Hong, Hyung Tae Kim, Dong Hyun Choi, Jin Hyeok Lee, Sunkook Kim, Hyun Jae Kim
Summary: Skin-conformable photoplethysmogram (PPG) sensors have been developed for continuous monitoring of heart rate and oxygen saturation, with features such as low power consumption, high reliability, and ease of operation. These sensors can operate separately at low and high heart rates, representing an innovative cardiovascular monitoring system that consumes less power and holds significance in the healthcare field.
Article
Materials Science, Multidisciplinary
Ki Woo Kim, Heesoo Lee, Hyun Jae Kim
Summary: This study proposes a new channel edge doping (CED) technique to reduce the hump effect in LTPS TFTs. By decreasing the electron concentration at the channel edge, the hump characteristic of LTPS TFTs can be effectively reduced. This technique is of great importance for manufacturing active-matrix organic light-emitting diode displays.
JOURNAL OF INFORMATION DISPLAY
(2022)
Article
Chemistry, Multidisciplinary
Scott T. Keene, Wesley Michaels, Armantas Melianas, Tyler J. Quill, Elliot J. Fuller, Alexander Giovannitti, Iain McCulloch, A. Alec Talin, Christopher J. Tassone, Jian Qin, Alessandro Troisi, Alberto Salleo
Summary: Traditional electronic transport models for conducting polymers focus on conjugated chains and ignore the contributions of nominally insulating components. This study demonstrates that the chemical structure of the non-conductive component has a significant effect on charge carrier mobility. By diluting the conducting polymer with excess insulator, blends with high insulator content can exhibit carrier mobilities comparable to pure conducting polymers. A single, multiscale transport model based on the microstructure of the polymer blends is developed to describe the transport properties for different dilutions. The results reveal that the high carrier mobility in primarily insulator blends is achieved through long-range tunneling mechanism facilitated by aromatic rings.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Yansheng Zhang, Malgorzata Nguyen, Christoph Schnedermann, Scott T. Keene, Ian Jacobs, Akshay Rao, Henning Sirringhaus
Summary: Charge modulation microscopy (CMM) is a method for mapping induced charges in an organic field-effect transistor (OFET). A new implementation of CMM in transmission geometry with camera-based imaging has been developed, resulting in a significant improvement in data acquisition speed while maintaining resolution. The system was demonstrated by measuring the spatial distribution of induced charges in an OFET with polymer blend, achieving high-resolution imaging.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Kyung Min Kim, Jeong Suk Yang, Hyung Tae Kim, Inhyo Han, Sang-Hoon Jung, Joon-Young Yang, Yong Min Ha, Soo Young Yoon, Hyun Jae Kim
Summary: This study investigates the back-channel interface engineering of oxide thin-film transistors (TFTs) using commercially available silicon oxide (SiOx) and its effects on the electrical characteristics of fully integrated TFTs. The proposed method effectively alleviates back-channel damage, promotes oxygen inter-diffusion, suppresses excess hydrogen inflow, and boosts out-diffusion of residual copper. The result is improved device uniformity and electrical characteristics, including high field effect mobility and significantly suppressed threshold voltage variation with decreasing channel length.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Won Kyung Min, Chihyeong Won, Dong Hyun Kim, Sanghyeon Lee, Jusung Chung, Sungjoon Cho, Taeyoon Lee, Hyun Jae Kim
Summary: A negatively responsive switch-type strain-sensor with twisted conductive fibers is developed that can significantly increase its conductivity from insulating to conducting properties. This sensor can regulate the mutual contact resistance under tensile strain while maintaining exceptional durability. Additionally, three healthcare monitoring systems with near-zero standby power are also developed, expanding the utilization range of fiber strain-sensors.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Jung Chul Kim, I. Sak Lee, Hyung Tae Kim, Jong Bin An, Jae Sung Kim, Juhn Suk Yoo, Han Wook Hwang, Hyun Chul Choi, Yong Min Ha, Hyun Jae Kim
Summary: This paper presents a new pixel circuit and driving scheme for mobile devices with AMOLED displays, utilizing LTPO TFTs. The proposed circuit and scheme ensure uniform luminance and eliminate flickering at various refresh rates. Experimental results demonstrate that extending the compensation time and applying a higher voltage to the D-TFTs effectively improve luminance uniformity and reduce flicker. A 6.0-inch QHD LTPO-based AMOLED display was successfully fabricated using this approach.
JOURNAL OF INFORMATION DISPLAY
(2023)
Editorial Material
Engineering, Electrical & Electronic
Hyun Jae Kim, Kirk Schanze, Chengmei Zhong
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Bogyeom Seo, Jusung Chung, Naresh Eedugurala, Jason D. Azoulay, Hyun Jae Kim, Tse Nga Ng
Summary: This study demonstrates the integration of an organic bulk heterojunction polymer layer on an oxide thin-film transistor to achieve high-efficiency photodetection in the short-wave infrared region. By using trap-assisted charge injection, the organic semiconductor's photoresponse at longer wavelengths is enhanced. The detector performance is optimized by investigating the balance between bias stress and signal-to-noise under different bias conditions, resulting in a responsivity at 1550 nm up to 130 mA/W at a low light intensity.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Physical
Scott T. Keene, Viktor Gueskine, Magnus Berggren, George G. Malliaras, Klas Tybrandt, Igor Zozoulenko
Summary: Efficient transport of both ionic and electronic charges in conjugated polymers has enabled a wide range of novel electrochemical devices. This Perspective provides an overview of the fundamental physical processes underlying the operation of mixed conducting polymer devices and highlights recent advances in this field. Challenges in further extending the understanding of MCP-based device operation are identified. A deeper understanding of the elementary processes governing operation in MCPs will drive materials design and device performance advancement.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Seung Hee Kang, I. Sak Lee, Kyungmoon Kwak, Kyeong Take Min, Nack Bong Choi, Han Wook Hwang, Hyun Chul Choi, Hyun Jae Kim
Summary: The effect of boron (B) implantation into the source/drain region of a self-aligned coplanar amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistor (TFT) on the electrical properties and device stability was investigated. The results showed that the electrical properties were optimized when the projection range of B was in the central vertical region of the film. B implantation decreased resistivity and improved field-effect mobility, and the fabricated TFTs exhibited excellent stability.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Jaidah Mohan, Yong Chan Jung, Heber Hernandez-Arriaga, Jin-Hyun Kim, Takashi Onaya, Akshay Sahota, Su Min Hwang, Dan N. Le, Jiyoung Kim, Si Joon Kim
Summary: This study investigates the correlation between imprint and polarization relaxation in ferroelectric HZO films, revealing the drastic relaxation effects due to imprint. Prepoled ferroelectric capacitors exhibit apparent imprint and strong polarization relaxation effects due to the development of built-in voltages.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Dennis Christensen, Regina Dittmann, Bernabe Linares-Barranco, Abu Sebastian, Manuel Le Gallo, Andrea Redaelli, Stefan Slesazeck, Thomas Mikolajick, Sabina Spiga, Stephan Menzel, Ilia Valov, Gianluca Milano, Carlo Ricciardi, Shi-Jun Liang, Feng Miao, Mario Lanza, Tyler J. Quill, Scott T. Keene, Alberto Salleo, Julie Grollier, Danijela Markovic, Alice Mizrahi, Peng Yao, J. Joshua Yang, Giacomo Indiveri, John Paul Strachan, Suman Datta, Elisa Vianello, Alexandre Valentian, Johannes Feldmann, Xuan Li, Wolfram H. P. Pernice, Harish Bhaskaran, Steve Furber, Emre Neftci, Franz Scherr, Wolfgang Maass, Srikanth Ramaswamy, Jonathan Tapson, Priyadarshini Panda, Youngeun Kim, Gouhei Tanaka, Simon Thorpe, Chiara Bartolozzi, Thomas A. Cleland, Christoph Posch, Shihchii Liu, Gabriella Panuccio, Mufti Mahmud, Arnab Neelim Mazumder, Morteza Hosseini, Tinoosh Mohsenin, Elisa Donati, Silvia Tolu, Roberto Galeazzi, Martin Ejsing Christensen, Sune Holm, Daniele Ielmini, N. Pryds
Summary: This article introduces the characteristics and advantages of von Neumann architecture and neuromorphic computing systems. While traditional von Neumann architecture is powerful, it has high power consumption and cannot handle complex data. Neuromorphic computing systems, inspired by biological concepts, can achieve lower power consumption for storing and processing large amounts of digital information. The aim of this article is to provide perspectives on the current state and future challenges in the field of neuromorphic technology, and to provide a concise yet comprehensive introduction and future outlook for readers.
NEUROMORPHIC COMPUTING AND ENGINEERING
(2022)